Resistance alloy



Patented Feb. 13, 1923.

UNM STATES F F] E.

JOHN H. WHITE, OF CRANFORD, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

RESISTANCE ALLOY.

No Drawing.

To all whom it may concern:

Be it known that 1, JOHN H. WHITE, a

citizen of the United States, residing at, Cranford, in the county ofUnion, State of New Jersey, have invented certain new and usefulImprovements in Resistance Alloys, of which the following is a full,clear, concise, and exact description.

This invention relates to resistance materials and has for its object animproved metallic alloy having a specific resistance many times that ofcopper, capable of withstanding high temperatures without deleteriousoxidation and sufficiently ductile and otherwise workable to permit itsformation into a filament or other forms suitable for use in theresistance elements for electric heating appliances and the like.

It has long been known that ferro-nickel alloys having more than nickelare capable of withstanding fairly high temperatures without excessiveoxidation. Such alloys have not, however, proven entirely satisfactoryfor use in electric heating appliances for the reason that in order toob tain the required electrical resistance it is necessary either to usea fine wire which is, therefore, not sufiiciently rugged to withstandthe frequent jars to which such appliances are subjected, or to use agreater length of a larger wire, thereby producing an unduly large andcumbersome heating element. v

I have found that if a portion of the iron in such ferro-nickel alloysbe replaced by tantalum, not only is the specific resistance of thealloy greatly increased but the resistance wires or filaments formedfrom it are much less subject to progressive oxidation and their lifewhen subjected to high temperatures is greatly increased. The new alloysare furthermore easily worked and can be drawn into any desiredfilamentary form.

In place of tantalum, columbium (niobium) may be used, and in fact forcom-' mercial production a combination of tan talum and columbium hasbeen found preferable for the reason that such a combination may be moreeasily and more cheaply obtained than either the pure tantalum or purecolumbium.

For example. the commercial ore known as tantalite when purified yieldsa mixture of the oxides of tantalum and columbium Application filedSeptember 22, 1919. Serial No. 325,461.

which can easily be reduced to the metallic state.

Resistance elements suitable for use in electric heating appliances canbe obtained by employing an alloy in which there is fromgrade for morethan 900 consecutive hours without deleterious oxidation.

While the alloy above described is seen to have four ingredients whenproduced in a commercial form, that is, nickel, iron, tantalum andcolumbium, the alloy is essentially a ternary alloy containing nickel,iron and a metal having the properties of tantalum, columbium being aconvenient substitute for the tantalum or; for a portion thereof.

The alloys described herein are also characterized by their resistanceto chemical reagents and to mechanical working. It has been knownheretofore that the resistance of nickel to acids is increased by theaddi tion of tantalum. But alloys of nickel and tantalum or columbiumare exceedingly hard to work and up to the present time have only beenmade by compressing the two metals in powdered form and then submittingthe mixture to heat. It has been found that if iron is added to thebinary alloy of nickel-tantalum or nickel-columbium ornickel-tantalum-columbium, a ternary or a quaternary alloy is obtainedwhich may be readily formed and worked. The characteristics which arepossessed by these ternary or quaternary alloys make them useful also inthe construction of cutlery, chemical ware, machine tools. etc.

What is claimed is:

1. A ferro-nickel alloy containing more than 60% nickel in which aportion of the iron is replaced by a material having the properties oftantalum.

2. An electric resistance element consisting of a ferro-nickel alloycontaining more than 60% nickel in which a portion of the iron isreplaced by a material having the properties of tantalum.

than 60% nickel in which a. portion of the having the properties oftantalum, approxiiron has been replaced by tantalum and comately 10% ofiron and the remainder of lumbium. nickel. s

4. A resistance element comprising an 6. A resistance element comprisingan 5 alloy containing from 70 to 80% nickel, the alloy containing 75%nickel, 11% iron and 15 remainder being composed of substantially 14%tantalum-columbium, equal parts of iron and a metal having the InWitness whereof, I hereunto subscribe properties of tantalum. my namethis 17th day of September A. D.,

5. A resistance element comprising an 1919. 10 alloy containing from 10to 20% of a metal JOHN H. WHITE.

